1. Field of the Invention
The present invention relates to an optoelectrical device, and more specifically to an organic light-emitting diode and method of fabricating the same.
2. Description of the Related Art
Generally, moisture may permeate an OLED device with long-term use, and, due to a highly activated metal electrode and the loose structure thereof, permeated moisture continuously reacts to the electrode and rapidly enters interior elements, resulting in cleavage of materials or dark spots, and reduced active lifetime of an OLED device.
Currently, compressing the surface structure of a metal electrode, and installing a power drying agent to absorb moisture are the primary methods of preventing moisture damage and prolonging the active lifetime of an OLED device.
Furthermore, various technologies for reducing interior humidity have been developed to eliminate dark spots, such as forming photo-hardened resin on the glass substrate, plating a metal oxide, fluoride or sulfide on the glass substrate, forming a water-resistant film on the glass substrate, and using an airtight case to package the OLED element. Nevertheless, other problems, such as leakage current, crosstalk and oxide dissolution, still exist.
An OLED structure is disclosed in U.S. Pat. No. 5,882,761, and represented in FIG. 1. Referring to FIG. 1, an organic light-emitting device includes a glass substrate 10, a sealing agent 9 composed of a UV-cured resin and smeared on the rim of the glass substrate 10, and a sealing case 7 bound to the rim of the glass substrate 10 by the sealing agent 9, forming an airtight space.
An illuminative body 6 is formed on the surface of the glass substrate 10, comprising an anode layer 3, an organic-emitting layer 4, and a cathode layer 5. A drying layer 8 is installed on the bottom and side walls of the sealing case 7, and dried inert gas is filled in an interior space 11 constituted by the drying layer 8 and the illuminative body 6. The drying layer 8 comprises a solid compound, such as BaO, CaO, CaSO4, and CaCl2, which chemically absorbs moisture and remains in a solid state. The drying layer 8 is a sheet body fixed on the concave of the sealing case 7 via bonding.
Moisture may also react to metal electrodes, if a drying agent provides less absorption than the metal electrodes, and process cost and a device size may increase due to installation thereof.